The ant species parasite significantly slows their aging, but this is undeniably to make it easier for them to swallow the bird, in which the intruder will complete its growth, according to a study published on May 19th.
“We have been monitoring insect survival for three years and show that infected ants live much longer than uninfected ones“, Susanne Foitzik, a professor of biology at the German University of Mainz, told AFP. And that’s an understatement, because no healthy ants have passed this milestone, while more than half of the parasitized ants were still alive, according to a study published in The open science of the Royal Society.
Temnothorax nylanderi (T. nylanderi), also called the acorn ant, where it makes a small nest, is a widespread species in Western Europe. Entomologists have long known that their working caste is the main target of parasites,Anomotaenia brevis (A. brevis). In adulthood this small worm, cespode tapeworm, lives in the digestive tract of woodpeckers. There he lays the eggs found in the bird’s feces, before they appear on the menu of larvae T. nylanderi. The eggs of the parasite then colonize their hemolymph (“ant” blood) and develop there in the form of larvae.
Infected ants seem to retain the form of eternal youth. Their foreskin, an exoskeleton that serves as their shell and skin, retains the pale yellow color of young ants, originally confined to the nursery. The parasite also modifies their behavior because they refuse to follow the working ants that dare to feed the anthill outside. “Why can I live so long?“, with a survival rate identical to that of queens, some of which reach twenty years of age, wonders Professor Foitzik, who signed the study with his former student Sarah Beros, now a researcher at the Institute. Max Planck.”Maybe thanks to more care“because”infected ants get more attention than other workers“, which seem to be attracted by a certain chemical signal from their exoskeleton. But a team of entomologists also found in a second study published in January 2021 that the presence of parasites”enhanced the expression of immunity-related genes, and to a lesser extent longevity-related genes“says the biologist. In other words, the parasite would help the ant’s body fight aging.
Even better, Professor Foitzik’s team analyzes the proteins released by the parasite in the “blood” of the ants, which “opens a window on the phenomenon of aging“.”We found that several of these proteins have antioxidant properties.“Very useful for the immune system,” she said, consideringit is possible that the parasite itself helps the ant to live longer“.”Why would a parasite try to prolong the life of its host?“Asks Foitzik. She responds to this in the study by assuming that this is the best way for the parasite to reach its final host. Because the parasite larva can only transform into a worm by finding a tube. Woodpecker digestive.
Other ant parasites lead them to suicide quickly to achieve their goals. The small liver fluke, which begins its cycle in the snail, turns into an ant species Formicaand forces its host to lose company with its relatives every day, who will settle on the grass, in the “hope” that a ruminant will fall, the ultimate target of the parasite. Another little worm, Myrmeconema neotropicum, causes its host ant to lift its red belly into the air, it better tempts the passing bird, its final host. Which brings us back to the woodpecker, who would have little chance of spotting it T. nylanderi and its largest size is 3 mm on a pile of leaves. Infected ants “stay protected in its nest on an acorn or branch, exactly where the woodpecker will open to feed on the larvae“, according to the study. It is therefore likely that the researchers’ behavioral changes observed in infected workers predispose the bird to work on them.